Commercial demand for small, portable, and power efficient electronic devices providing a variety of functions and features is growing at an exponential pace. There is an increasing demand to enable systems and methods for wirelessly providing power to electronics. Significantly, it may be possible to power miniature passive electronic devices and potentially even common portable electronic devices, such as cellphones, GPS systems, and media players, via a wireless input signal. The potential applications for wirelessly powered devices is tremendous, yet, the range, reliability, and power efficiency of conventional wirelessly powered systems is limited.
For example, Radio Frequency Identification (“RFID”) is increasingly popular in implementations for tracking inventory, retail merchandise, airport baggage, and other items. Passive RFID systems rely upon RFID tags to receive data and power from an input waveform broadcast by an interrogator. Conventional RFID systems provide a limited range in which communication can be established between a RFID interrogator and an RFID tag. In some embodiments, an RFID tag cannot establish communication unless it is within 1 meter of the RFID interrogator. In addition to limited range, conventional RFID tags exhibit rather limited power efficiencies. Therefore, a large percentage of the power emitted from an RFID interrogator cannot be harvested by the integrated circuit of the RFID tag.
Prior art systems and devices have attempted to increase and improve the range and power efficiency of wirelessly powered devices by modifying and tweaking the design of the wirelessly powered device. For example, certain conventional wirelessly powered devices have attempted to limit the number of charge pumps active in a device at any one point. Alternatively, conventional wirelessly powered devices have implemented power management units on the device in an attempt to more efficiently manage the power consumed by the device. Although many prior art attempts have been made to improve the wirelessly powered device, very few have been made to improve the power waveform received by the device.
Therefore, it would be advantageous to provide a wireless power transmission system that would enable an increased range and reliability for wireless devices by improving the power waveform received by the device.
Additionally, it would be advantageous to provide an optimized waveform input for wirelessly powered devices.